Hot cells for handling high radiation level sources remotely with manipulator arms are well-known. Generally, they have thick, poured concrete walls, ceilings and floors, as necessary, to attenuate the gamma radiation from the sources during handling within the cell. Manipulator arms are provided, together with a window and/or television camera and monitor, so that an operator can handle the high radiation level sources within the hot cell from exterior of the cell.
These hot cells generally have been permanent installations in the past. It may have been proposed to make a portable, self-contained lead hot cell, but this would not have been practical if proposed. It has been known to have a loading device as part of a shipping cask for gamma sources, but these loading devices have limited application to, for example, handling one or two sources. Additionally, it has been proposed to use concrete blocks notably in nuclear power plants to provide shielding to protect workers during performance of the repairs and the like, but these have not been used to provide a temporary hot cell integral with the building structure.
The need for a temporary or semi-temporary hot cell for transfer of high radiation level sources at field locations, such as hospitals, has become evident with the development of complex medical devices which require multiple high radiation level sources, e.g., the Leksell Gamma Knife Unit, using over 200 Cobalt 60 sources of 30 curies each. Heretofore, it was necessary to transport the medical device to a permanent hot cell where the high radiation level sources would be loaded into and unloaded from the device. Although it may be necessary only to replace the radiation sources every five to ten years, this still presented a very difficult problem because of the increased costs and also because of laws and regulations limiting or prohibiting transporting such devices containing high radiation sources.